In many applications, autonomous mobile robots are used to perform functions in place of humans or to assist humans in order to increase productivity and efficiency. One such application is order fulfillment, which is typically performed in a large warehouse filled with products to be shipped to customers who have placed their orders over the internet for home delivery.
Fulfilling such orders in a timely, accurate and efficient manner is logistically challenging to say the least. Clicking the “check out” button in a virtual shopping cart creates an “order.” The order includes a listing of items that are to be shipped to a particular address. The process of “fulfillment” involves physically taking or “picking” these items from a large warehouse, packing them, and shipping them to the designated address. An important goal of the order-fulfillment process is thus to ship as many items in as short a time as possible. In addition, the products that will ultimately be shipped first need to be received in the warehouse and stored or “placed” in storage bins in an orderly fashion throughout the warehouse so they can be readily retrieved for shipping.
Using robots to perform picking and placing functions may be done by the robot alone or with the assistance of human operators. One system which utilizes autonomous mobile robots with the assistance of human operators is described in U.S. Pat. No. 9,758,305. With this system, robots navigate to poses (consisting of the x,y,z coordinates in the warehouse along with the orientation or the quaternion (x,y,z, ω) associated with each item they need to retrieve for an order. Once at the pose, a human operator can read the details of the item to be picked from, for example, a tablet on the robot, pick the item to be retrieved from the appropriate bin located on a shelf unit, and place it on the robot. While this is a very efficient system that supports very high order throughput, efficiencies may be improved in certain situations by allowing the human operators to assume limited manual control.